The killers of Saudi journalist Jamal Khashoggi poured his remains down the drain after dissolving him in acid, a Turkish newspaper reported Saturday.

Samples taken from the drains at the Saudi consulate in Istanbul showed traces of acid, pro-government daily Sabah said, without quoting sources.

This led investigators to believe the dead body of the insider-turned-critic of the Riyadh regime was disposed of through the drains as liquid, the paper said.

Khashoggi was last seen entering the consulate on October 2 to obtain documents for his forthcoming marriage. His body has never been found.

After repeated denials, Saudi Arabia finally admitted the 59-year-old had been murdered at the mission in a "rogue" operation.

However, Turkish President Recep Tayyip Erdogan has accused the "highest levels" of the Saudi government of ordering the hit, while some officials have pointed the finger at the all-powerful Crown Prince Mohammed bin Salman.

"They killed you and chopped up your body, depriving me and your family of conducting your funeral prayer and burying you in Madinah as wished."

A Turkish official this week confirmed a Sabah report that chemicals expert Ahmad Abdulaziz al-Janobi and toxicology expert Khaled Yahya al-Zahrani were among a team sent from Saudi amid investigations into the murder.

The paper said they visited the consulate every day from their arrival on October 11 until October 17. Saudi Arabia only allowed Turkish police to search the building on October 15.